Colombia scored twice in six minutes in a lively second half to beat Ivory Coast and move to the brink of the knockout stage.
James Rodriguez's powerful header from a corner in the 64th minute was quickly followed by a low finish by substitute Juan Quintero, securing the South American team's second straight win in Group C in front of a partisan pro-Colombian crowd.
Gervinho reduced the deficit in the 73rd with a superb run and shot inside the near post, but the Ivory Coast could not find an equalizer despite a strong finish.
A point against Japan in its third game will definitely seal qualification for Colombia but it could be secured before that, depending on the result of Japan vs. Greece later Thursday.
Ivory Coast still may need to beat Greece if it is to progress from the group stage for the first time at a World Cup.
There was a sea of yellow shirts throughout the Estadio Nacional as Colombia fans arrived en masse to the Brazilian capital, giving it the feel like of an intimidating away game for the Ivorians. The crowd roared with relief at the final whistle, with their team in touching distance of the second round of the World Cup for only the second time.
All this without star striker Radamel Falcao, who is missing the tournament through injury.
However, at halftime, the noise coming from the stands was not so fierce, with Ivory Coast holding relatively firm — except for a golden chance spurned by Teofilo Gutierrez in the 28th.
Rodriguez's left-wing cross fell perfectly for Gutierrez just outside the six-yard box, but he miscued his volley and it skewed wide.
With Yaya Toure seemingly anonymous and Didier Drogba again starting on the bench, Ivory Coast threatened only through long-range shots in a first half marked by a comic moment when a large inflatable ball bounced onto the playing surface, causing a brief stoppage.
Juan Cuadrado lit up a cagey opening to the second half by bringing down a long pass, shimmying past his marker and rifling a powerful shot that was tipped onto the crossbar by goalkeeper Boubacar Barry. Inside a stadium named after 1960s World Cup star Mane Garrincha, it was a piece of right-wing trickery that even the Brazil great would have enjoyed.
Drogba entered on the hour, to a mixture of jeers and applause, but he was found wanting in the leadup to Rodriguez's goal four minutes later, the playmaker beating him to Cuadrado's corner and heading powerfully into the net for his second goal of the tournament.
The celebrations had hardly died down when Ivory Coast midfielder Serey Die was dispossessed inside his own half, allowing Gutierrez to create a chance for Quintero, who made no mistake with a side-foot finish.
In a frenetic last quarter of the match, Ivory Coast — driven by Drogba — finished strongly.
Gervinho's goal was one of the best pieces of individual skill so far at this World Cup, the Roma winger skipping between two defenders, cutting inside a third and beating David Ospina at his near post. But there was to be no equalizer.